Polyphenylene ether resins are well known in the art and exhibit a desirable combination of chemical, physical and electrical properties over a wide temperature range. This combination of properties renders polyphenylene ether resins suitable for use in a broad range of applications. Often times, polyphenylene ether resins are blended with other resins in order to improve their chemical resistance, their processability and/or other properties and to increase their fields of application.
For example, the White et al U.S. Pat. No. 4,431,779 discloses blend compositions comprising a polyphenylene ether and a polyetherimide. The blends are disclosed as disclosing good impact strength as well as good mechanical properties. The Holub et al U.S. Pat. No. 4,873,287 discloses blend compositions comprising a polyphenylene ether, a polyetherimide and a block copolymer of a vinyl aromatic compound and an alkene compound. The blends are disclosed as exhibiting high glass transition temperatures and excellent flexural properties.
Often times, phosphorus and/or halogen containing materials are added to polyphenylene ether resins in order to improve the fire retardant properties of the resins. However, the use of such phosphorus and/or halogen containing materials can be disadvantageous for several reasons. For example, halogen-containing materials can sometimes react during resin processing to form corrosive by-products. The copending Rock application Ser. No. 07/563,750 filed Aug. 3, 1990 discloses blend compositions comprising a polyphenylene ether and a polyetherimide siloxane copolymer. The compositions are disclosed as exhibiting low flammability, and are advantageous in that they do not require phosphorus and/or halogen containing materials. Flame retardant silicone-polyimides are also disclosed in the Cella et al U.S. Pat. Nos. 4,690,997 and 4,808,686.
Owing to the increasing demand for use of polyphenylene ether resin compositions in various applications, there is a continuing need to provide such compositions having improved combinations of properties.